/Engine/Plugins/Experimental/ChaosCaching/Source/ChaosCaching/Public/Chaos/ChaosCache.h
Initialise the cache for playback, may not take any actual action on the cache but will provide the caller with a valid cache user token if it is safe to continue with playback
[FCacheUserToken](API\Plugins\ChaosCaching\Chaos\FCacheUserToken) BeginPlayback()